Drawings-in- of paper webs

ABSTRACT

A paper web is drawn into a printing and can be guided along a selected one of several paths. The paper web is weakened along a line of separation and is then held by a retaining system that can move the web in a conveying direction along a first path. The web is fed to a different conveying path and is separated ot torn along the line of separation. This line of separation or weakening is formed at an angle to the production direction.

FIELD OF THE INVENTION

The present invention relates to a method and to a device for drawing ina paper web, as well as to a corresponding device.

DESCRIPTION OF THE PRIOR ART

It is known, from DE 25 32 168 C3, to draw in webs of material to beprinted, for example paper webs, from a roll support to a foldingapparatus of a web-fed rotary printing press by means of web draw-indevices. It is also possible to select different movement tracks for thewebs of material to be printed.

U.S. Pat. No. 5,279,195 A describes a device for separating a defectivesection of a web. In the process, the web is cut, the fresh start ofthis web is guided to another web guide and this start is again cut offthe web. The now fresh start is again guided to the original web guide.

EP 0 479 385 A1 discloses a device for cutting perforated sheets. Here,two pairs of rollers are arranged, between which the sheets are conveyedat different conveying speeds.

EP 0 297 282 A1 shows a device for dividing a flow of printed pieces. Inthis case, a web is cut into signatures by means of two eccentricallyseated cutting cylinders and is alternatingly guided onto two tracks.

DE 196 26 014 A1 describes a device, having an air-permeable conveyorbelt, for cutting a fleece into longitudinal sections. Here, a part ofthe fleece is held in place by means of suction air, and the other partis moved on in the conveying direction.

SUMMARY OF THE INVENTION

The object of the present invention is based on providing a method forguiding a paper web, as well as an associated device.

In accordance with the present invention, this object is attained bycreating a fresh or new start on a paper web in a direction transverseto the web travel direction. The web is separated at this new start andthe path of travel of the web subsequent to this new start can bechanged to a second, different web travel path.

The advantages to be obtained by the present invention consist, inparticular, in selectively rerouting one of a number of moving paperwebs, or one or several partial paper webs, independently of each otheronto predeterminable movement tracks, without it being required to stopthe press, or the system, or for the operators to rehang the webs or thepartial webs. In connection with a web-fed rotary printing press, forexample, it might be possible to make a movement track change of a web,or of a partial web, while production is running.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention is represented in thedrawings and will be described in greater detail in what follows.

Shown are in:

FIG. 1, a schematic representation of a side view of a device fordirecting a path of web or partial web travel in accordance with thepresent invention,

FIG. 2, a section taken along line II—II of FIG. 1 and in an enlargedrepresentation, and in

FIG. 3, a view from above in accordance with FIG. 1, but without theconveyor belts.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A device 3 for reducing the tear resistance of a paper web 1 moving inthe production direction E of the web is provided, as seen in FIG. 1.This device 3 can consist, for example, of a transverse perforationdevice, or also of another similar device, for example a device, such asa plurality of nozzles for applying a liquid track of a solvent or watertransversely over the width of the web 1, or respectively over thewidths of partial webs 16, 17, 18, 19 to be processed. Viewed in theproduction direction E of the web, the web tear resistance reducingdevice 3 can be arranged ahead of, or behind a longitudinal separatingdevice 2, known per se, of the moving paper web 1.

The transverse tear resistance reducing device 3 can consist of formingrollers 4 and of bottom rollers 6, which can be placed against eachother. The paper web 1 in a first movement track A, can be rerouted outof the movement track A, or into a further movement track, for examplethe movement track B, or into a further movement track C. For example,the movement track A may extend essentially horizontally between twofirst forwarding systems 8, 8. The movement track B may extendunderneath the movement track A, wherein the paper web 1 is reroutedover two paper guide rollers 9, 11. The movement track C may extendabove the movement track A between two second forwarding systems 7, 7.

The first and second forwarding systems 7, 8 are each devices forgrasping and temporarily forwarding a part of the paper web 1, or thepartial paper webs 16, 17, 18, 19. They can be, for example, so-calleddriven suction belts, suction rollers, or electrostatic belt devices. Aplurality of deflection rollers 14 can be provided for rerouting.

The paper web 1 can also be longitudinally cut into several partialpaper webs 16, 17, 18, 19. A longitudinal cutting device 2, or aplurality of longitudinal cutting devices 2, as seen in FIG. 3, andwhich are known per se, can be used for this purpose.

Viewed in the production direction E of the paper web 1, a device 13, ordevices 21 to 24 for grasping a start of a web 1 of material, or startsof partial webs of material 16 to 19, respectively, at their upperand/or undersides and for their subsequent rerouting into a secondmovement track, for example B or C, and back, are provided in the firstmovement track A, after the device for reducing the tear resistance ofthe web 1, or the partial webs 16, 17, 18, 19, and before the forwardingsystems 7, 8. For example, this rerouting device can be used forrerouting webs from movement tracks A+C only into the movement track A,or from the movement tracks A+B back toward the movement track A, orfrom the movement tracks A+B toward the movement track A+C, etc. In thisphase, the web, or a partial web, is clamped under tensile stressbetween two spaced-apart devices. For example, this can occur betweentwo pairs of drawing rollers, between one pair of drawing rollers andcylinders (for example rubber blanket cylinders) of a print unit, orbetween cylinders of two spaced-apart print units. The web 1, or thepartial webs 16 to 19, are therefore clamped between two suchspaced-apart devices, while a web tension is maintained, and they arepulled apart or separated.

It is accordingly to select the number of partial webs per movementtrack (A, B, C), and therefore the composition and number of pages ofthe signatures, in a particularly simple manner. This is, of course,dependant on the occupation of the print units. Web transfers, known perse, are required for this.

The following actions take place:

The clamped paper web 1, or the clamped partial web 16, each move alonga movement track, for example A. By the application of a force throughthe devices 13, 21 to 24 for rerouting a web on their upper and/orundersides, the web 1 or the partial web 16 are pulled out of theiroriginal movement track, for example A, and are directed onto anothermovement track, for example movement track B, or movement track C.Because the device 21 to 24 for rerouting has a device 44 for holdingand conveying of the web or the partial web, as seen in FIG. 2, the heldweb 1, or the partial webs 16 to 19 are therefore simultaneously movedalong the former movement track, for example movement track A, and alongthe newly selected movement track, for example movement track C, and isor are accordingly separated at a predetermined breaking point or at apredetermined tear line formed by transverse perforations or by a watertrack made in the web 1, or partial webs 16 to 19 by the device 3. Thisoccurs because the tear resistance is exceeded by the pulling forceexerted on the web or the partial web at the predetermined transversebreaking point formed by the device 3. The affected web or the partialweb is completely separated in such a way, that a “fresh” web end 5 anda “fresh” web start 15 are created. Together with its “fresh” web end 5,the web 1, or respectively the partial webs 16, 19, are pulled, forexample, along their former movement track by drawing rollers, printingunits, etc. The “fresh” web start 15 of the web 1, or of the partialwebs 16 to 19, as well as the latter themselves, are held by the devices21-24 for rerouting , are moved along the newly selected movementtracks, for example C, and are finally transferred to a forwardingsystem, for example 7, and are transported to an intended destination,such as, for example, a pair of drawing rollers, a print gap of a printunit, and taken over by them.

The shape of the predetermined breaking point or of the predeterminedtear point can actually be designed in almost any arbitrary manner.

For example, the break or of tear point can be embodied as anacute-angled tip in the shape of a right triangle starting at one of thelateral edge, or also as a simple, non-oblique, i.e. straight tear.

The devices 13, or 21 to 24 for rerouting, which are suitable forrerouting, holding and conveying a web 1, or a partial web 16 to 19, forexample can consist of a suction belt station, or of several suctionbelt stations 21 to 24, arranged next to each other and each centeredover one partial web 16 to 19 of material to be printed. The suctionbelt stations 21 to 24 are each constructed the same. Only the suctionbelt station 21 shown in FIGS. 1 and 3 will be described in whatfollows.

The suction belt station 21 consists of several suction chambers 26, 27,28, 29 which, viewed in the production direction E of the web, arearranged one behind the other. Each chamber 26, 27, 28, 29 is closed onfive sides and has, for example, a trapezoidal cross section as seen inFIGS. 1 and 2. On their lower, wider bases 31, these chambers areflexibly connected with each other, for example by hinges. The narrowupper bases 32 are slightly convexly arched and have a plurality ofholes. The narrow upper bases 32 are held apart adjustably by means ofturnbuckles 33. Such an arrangement of the chambers 26 to 29 selectivelymakes a straight, a convexly curved, or a concavely curved suction trackpossible.

A start 34 and an end 36 of each suction belt station 21 has, viewed inthe production direction E, a holder 37, 38, which is connected with itsrespective chamber 26, 29 and which supports a front belt roller 39, ora rear belt roller 41, respectively. All cylinders, rollers, and thelike are seated in lateral frames 45, 50, as seen in FIG. 3 the same asthe holder 37.

On their lower, wider bases 31, the chambers 26 to 29 have, viewed inthe production direction E, guides 42, 43 on the left and right,respectively for a revolving suction belt 44. The suction belt 44 hasspaced apart holes 46, 47, 48, 49, 50 over its entire length and width,which intermittently and alternatingly overlap holes 52, 53, 54, 55, 56made in the lower, wide base 31 of the chambers 26 to 29, all as seen inFIG. 2.

The suction belt 44 is guided over both belt rollers 39, 41. The beltroller 39 is driven, for example, in such a way that on its side closeto the web, the suction belt 44 travels at the speed of the press and inthe production direction E. This drive is provided, for example, viatoothed belts from the device 3 for reducing tear resistance, forexample by means of an rpm-controllable electric motor.

Each chamber 26 to 29 has a connector 58 on its side, to which air lines60, 61, 62, 63 respectively are connected. These air lines can beselectively connected with a suction air source or with a compressed airsource. In this way, a plurality of chambers 26, 27, 28 can be chargedwith suction air, and at least the last chamber 29 can be changed withcompressed air.

The delivery end 36 of the suction belt station 21 can be adjusted inheight, for example by means of a work cylinder 64 which, at one end, isfixed in place on the suction belt station, and whose opposite support45 is seated on a cross bar 51, which is fixed in place on the lateralframe.

In accordance with another preferred embodiment, the device 13 forrerouting, having a device for holding and conveying, can also bedesigned as a rotatable suction roller 13 air is provided to it via arotating connector, not represented. In this case, it is possible tocharge either the entire width of the suction roller 13 corresponding tothe width of the web 1 of material to be printed, or to charge only oneof several portions of the width of suction roller 13, corresponding tothe width of a partial web or webs 16, 17, 18 or 19, with suction air.Approximately 270° of the interior circumference of the suction roller13 is covered with a sealing coat 20, so that the suction only becomeseffective at the circumference of the suction roller 13 against whichthe web 1 or the corresponding partial web or webs 16, 17, 18 or 19 isresting and at an amount of an angle β of approximately 90°. From avertex line 71 on the surface of suction roller 13, which is a linewhere a change in the movement direction of the web 16 from onedirection—for example a horizontal direction—into another direction—forexample a vertical direction—takes place, the web 1 or the partial web16 tears transversely along a predetermined cutting or tear line 68. Thefresh web end part 5 of the partial web 16 continues to run over thepaper guide rollers 9, 11 in the movement track B. The torn off part ofthe partial web with the fresh web start 15 continues to run along themovement track A and possibly from there onto another movement track,for example movement track C. In the process, the “fresh” start 15 ofthe partial web 16 is still aspirated in the area of the next to thelast chamber 28, and in the area of the last chamber 29 it is pushedaway by means of compressed air, and in this way is brought between theupper and lower belts of a forwarding system 7 and from there onto apreselected movement track, for example movement track C.

The method for transversely separating and changing the direction of amoving web of material to be printed, for example a paper web 1,operates as follows: a full-width paper web 1 moving in the productiondirection E is longitudinally cut into four quarter-width partial paperwebs 16 to 19 by means of the longitudinal cutting devices 2 and isguided by the paper guide rollers 9 onto a first movement track A. Thefor example, left partial web 16 is provided with a predeterminedseparation or tear line 68 or 69, as depicted in FIG. 3, for example inthe form of a transverse perforation line or a transverse water track,at a predetermined angle±α, for example 0° to 60°, and preferably 45°,in respect to a lateral edge 66 or 67, or in respect to the partialpaper web 16, by means of a device 3 for reducing the tear resistance ofthe web, for example the transverse perforation device 3. Following theseparation of the web 1, or the partial web 16, in the manner discussedabove, a “fresh” web end 5 and a trailing “fresh” web start 15 of theweb 1, or of the partial web 16, is created.

It will be understood that+α a means that the angle a is in reference tothe right lateral edge 67 of the partial web 16, and that−α means thatthe angle a is in reference to the left lateral edge 66 of the partialweb 16.

The suction belt station 21 arranged above the partial web 16, forexample at a short distance “d”=one millimeter, is charged withcompressed and suction air. The first chambers 26 to 28 are charged withsuction air, and at least the last chamber 29 is charged with compressedair. The web or the partial web is aspirated and is held against thesuction belt 44.

The web 1 or the partial web 16 is to be rerouted from the movementtrack A onto the movement track C in the following discussion. The web 1or the partial web 16 moving, for example, in the movement track A, hasa speed which is equal to the circumferential speed of the suction belt21. The suction belt 21 aspirates the partial web 16, which is to bererouted, in such a way, that it does not slip, if possible, andattempts to move or to draw it onto the new, preselected movement track,for example the movement track C. This means that the partial web 16 ismoved in the movement track A, as well as in the movement track C.Because of this, the tensile stress exerted on the partial web 16increases until the artificially generated reduction of the tearresistance of the partial web 16, created by the device for reducingtear resistance 3, is exceeded and the partial web 16 is transverselyseparated along a preselected or predetermined break line or tear line68 or 69. A part of the partial web 16 continues to run in the movementtrack A, and the torn off part is conveyed on in the movement track C.

After the termination of the transverse separation and directionchanging process, the air supply is cut off and the suction air station21 is removed by means of the work cylinder 64 from the vicinity of thepaper web 1 or the partial web 16, i.e. the suction air station 21 ispivoted up.

It is also possible to transfer one or several other partial websdownward onto a different movement track. This can take place bydisplacing the chambers 26 to 29 and the suction belt stations 21 to 24in respect to each other in such a way, that the suction belt stations21 to 24, and thus the suction belts 44 now have a concave shape inplace of a convex shape. Therefore, separation of the paper webs orpartial paper webs takes place by holding them and changing theirdirection.

A device for the complete transverse separation of the paper web 1, orfor all of the partial webs 16 to 19 can also be provided. For example,this device may consist of a cutter holder, which can be moved up anddown and which has a cutter that works together with a counter cutterfixed in place on the frame. The paper web 1, 16 to 19 is stopped ormoves slowly, and is then transversely cut. During this process, thepaper web 1, 16 to 19 is held by suction belts 44 via chambers, asdescribed above. Two suction belt systems 44 are provided, which canboth be driven and which are arranged one after the other, viewed in theproduction direction. The cutter moves up and down between the twosuction belt systems 44 and transversely cuts the paper web 1, or thepartial paper webs 16 to 19. In the process, a fresh web end 5 and afresh web start 15 are created. The fresh web end 5 is held by the frontsuction belt system 44 and is conveyed on. The fresh web start 15 isheld by the rear suction belt system 44, as viewed in the productiondirection E, and is subsequently conveyed on.

While preferred embodiments of a device for drawing-in paper webs, and amethod for its use in accordance with the present invention have beenset forth fully and completely hereinabove, it will be apparent to oneof skill in the art that a number of changes in, for example, the sourceof supply of the paper web or webs, the type of printing press used, andthe like can be made without departing from the true spirit and scope ofthe present invention, which is accordingly to be limited only by thefollowing claims.

What is claimed is:
 1. A method for drawing in a partial paper web in aprinting press including; providing a plurality of laterally spacedpartial paper webs; providing a first movement path for said pluralityof laterally spaced partial paper webs; drawing in said plurality oflaterally spaced partial paper webs next to each other in a productiondirection along said first movement path; forming a line of separationin at least one of said plurality of partial paper webs, said line ofseparation extending transverse to said production direction; providinga second movement path, different from said first movement path, forsaid plurality of laterally spaced partial paper webs; moving said atleast one of said plurality of partial paper webs with said formed lineof separation before, in said production direction, said line ofseparation along said first movement path; moving said at least one ofsaid plurality of partial paper webs with said formed line of separationafter, in said production direction, said line of separation along saidsecond movement path; separating said at least one of said plurality ofpartial paper webs in a direction transverse to said productiondirection along said line of separation in response to said movement ofsaid at least one of said plurality of partial paper webs along bothsaid first movement path and said second movement path; forming a freshpartial paper web start in said at least one of said plurality ofpartial paper webs at said now separated line of separation; and movingsaid at least one of said plurality of partial paper webs following saidfresh partial paper web start along said second movement path differentfrom said first movement path.
 2. A method for guiding a paper webincluding: providing a paper web; providing an original movement trackfor said paper web; drawing said paper web along said original movementtrack in a production direction; forming a line of weakening in saidpaper web in a direction transverse to said production direction;reducing the tear resistance of said paper web at said line ofweakening; providing a new movement track for said paper web, said newmovement track being different from said original movement track;guiding said paper web with said line of weakening, after, in saidproduction direction, said line of weakening, onto said new movementtrack, different from said original movement track, by applying a forceto one of an upper and a bottom surface of said paper web after, in saidproduction direction, said line of weakening; transversely separatingsaid paper web, whose tear resistance has been reduced at said line ofweakening, in response to said guiding of said paper web, after saidline of weakening, to said new movement track; forming a fresh end ofsaid paper web and a fresh start of said paper web which has beentransversely separated at said line of weakening; moving said freshstart of said paper web along said new movement track; and moving saidfresh end of said paper web along said original movement track.
 3. Amethod for guiding a paper web including: providing a paper web;providing a first movement direction for said paper web; moving saidpaper web along said first movement direction; weakening the tearresistance of said paper web along a tear line extending at an anglewith respect to said first movement direction across said paper web;providing a second movement direction for said paper web different fromsaid first movement direction; rerouting said paper web, after said tearline, into said second movement direction; moving said paper web, aftersaid tear line, along said second movement direction; and separatingsaid weakened tear resistant paper web at said tear line in response tosaid rerouting of said paper web, after said tear line, from said firstmovement direction to said second movement direction.
 4. The method ofclaim 3 wherein said angle is in a range of 30° to 60°.
 5. A device fordrawing in paper webs into a web-fed rotary printing press comprising: afirst paper web movement path extending in a production direction; apaper web tear resistance reducing device in said first movement pathand transverse to said production direction and adapted to form a lineof weakening in a paper web passing through said paper web tearresistance reducing device; a second paper web movement path differentfrom said first paper web movement path and extending in said productiondirection; a suction station in said second paper web movement path, andafter, in said production direction, said paper web tear resistancereducing device, said suction station having a plurality of suctionsections; and means providing suction air to each of said plurality ofsuction sections, said suction sections each being adapted to draw apaper web to said suction station and to separate a paper web at a lineof weakening in response to movement of a paper web with a line ofweakening along both said first paper web movement path and said second,different paper web movement path.
 6. The device of claim 5 wherein saidfirst and second movement paths are on separate levels.
 7. The device ofclaim 5 wherein said suction station includes a suction belt.
 8. Thedevice of claim 5 wherein said suction station has first and second endsand further wherein one of said first and second ends is heightadjustable.
 9. The device of claim 5 wherein each of said suctionsections includes several chambers which are arranged one behind anotherin said production direction.
 10. The device of claim 9 further whereinsaid plurality of suction sections each further includes a plurality ofsuction holes.
 11. The device of claim 9 wherein said suction belt has aplurality of belt holes.
 12. The device of claim 11 further wherein saidplurality of suction sections further include a plurality of sectionholes.
 13. The device of claim 9 further including means hingedlyconnecting said several chambers together to define a shapeableconveying track.
 14. The device of claim 9 further including a source ofair under pressure and further including means to selectively connecteach of said chambers to said source of air under pressure.
 15. Thedevice of claim 9 further including means hingedly connecting saidchamber together to define a shapeable conveying track adjacent to saidpaper webs.
 16. The device of claim 7 further including anrpm-adjustable electric motor useable to drive said suction belt. 17.The device of claim 5 wherein said paper web tear resistance reducingdevice is a transverse cutting device, and further including a clockcontrol for said transverse cutting device.
 18. The device of claim 17wherein said transverse cutting device includes a cutter, said cutterhaving a movement path between adjacent ones of said suction sectionsarranged in said direction of web travel.